On 2021-11-10, Sultan Alsawaf <sultan@xxxxxxxxxxxxxxx> wrote: > On Wed, Nov 10, 2021 at 11:13:37AM +0106, John Ogness wrote: >> Even after we introduce kthread printers, there will still be >> situations where direct printing is used: booting (before kthreads >> exist) and shutdown/suspend/crash situations, when the kthreads may >> not be active. > > Although I'm unaware of any ongoing kthread printer work, I'm curious > to know how a kthread approach wouldn't employ a try_to_wake_up() from > directly inside printk(), since the try_to_wake_up() hit from inside > the fbcon code is what caused my deadlock. The kthread approach triggers irq_work from printk(). The kthread printer is then woken from the irq_work. John Ogness
